The influence of relatedness on parental reproductive success and offspring fitness in Eastern chipmunks breeding in fluctuating environments

Mate choice and multiple paternity have been widely studied in natural populations, especially in research assessing inbreeding avoidance mechanisms. Ecological factors are expected to affect the costs and benefits of mate choice and multiple paternity, for instance through their effects on availability of partners. However, the relative importance and variation of those costs/benefits across fluctuating environmental contexts remains to be established. Here, we used reproduction data collected over 18 years on a wild population of Eastern chipmunks (Tamias striatus) to assess the influence of relatedness among mating partners on their reproductive success and on their offspring fitness in different breeding contexts. In southern Québec, chipmunks live in a pulse resource system where they anticipate masting events of the American beech (Fagus grandifolia) and breed during the summer preceding and/or the spring following a mast. We found that, within a litter, less genetically related s..., , , # The influence of relatedness on parental reproductive success and offspring fitness in Eastern chipmunks breeding in fluctuating environments

This dataset contains 6 Excel spreadsheets used to perform all analyses described in the paper The influence of relatedness on parental reproductive success and offspring fitness in Eastern chipmunks breeding in fluctuating environments (Journal of Evolutionary Biology, 2025). All methods are described in the paper.

## Description of the data and file structure

### Data\_IR\_vs\_Rxy.xlsx

This spreadsheet presents Eastern chipmunks data related to juveniles and their parents (Rxy and IR). It contains one line per juvenile.

Juvenile is a column that indicates the Juvenile's ID
Dam is a column that indicates the Dam's ID
Sire is a column that indicates the Sire's ID
Rxy is a column that indicates the Parental relatedness of the juvenile's parents
IR is a column that indicates the Internal relatedness of the juvenile's parents (IR; metric of in...,